The touch-enabled Firefox features large targets for adding a new tab -- the "+" symbol on the right -- and steering back to the previous page with the back arrow at the left. Unlike the desktop edition, the Metro-ized Firefox -- the one suited for Windows 8's and 8.1's tile-based, touch-first user interface (UI) -- places the address bar at the bottom of the window.

The browser can be full-screen or 'snapped' to fill part of the screen

Firefox for Windows 8 Touch -- the mouthful that Mozilla's named the browser -- can be a full-screen app in the Metro UI, or can be "snapped" or "filled" to occupy just part of the screen. Here the browser is open while Windows 8.1's native Bing Weather fills the rest of the display.

Open tabs are represented by large thumbnails, and are accessed by swiping down from the top middle of a touchscreen. Touching one of the thumbnails brings up that tab's page, while the "+" symbol at the right creates a new tab.

Keeping to the simplicity of the Metro UI, Firefox has only a few option settings, which are accessed by touching the Settings charm after swiping in from the right.

Among those options is one to set "Do Not Track," the anti-monitoring standard that appears to be dead in the water, reviled by online advertisers. By default, Firefox for Windows 8 Touch sends no signal.

But although Mozilla has crafted an impressive Metro browser, it's being released just as Microsoft is backing away from the UI. Windows 8.1 Update 1, now seemingly set to debut in early April, will continue the retreat from Metro, the Start screen and its apps by reinstating several more features it originally had yanked from the desktop mode.